Roche has decided not to license an antifungal product developed by fellow Swiss company Basilea Pharmaceutica, but the latter says it will press ahead with development of the drug on its own.

Basilea’s investors seemed unmoved by the announcement earlier today. The company’s share price had barely shifted from its opening price of 137 Swiss francs, and was at 136 francs in mid-morning trading.

Roche had an option to license the antifungal, BAL8557, which has been shown to be at least as effective as a comparator drug (fluconazole) in the treatment of oesophageal candidiasis in a Phase II study. Now, Basilea has said it will take the drug into Phase III trials next year. Planned trials will target severe invasive yeast (candida) and fungal infections (including aspergillus and zygomycetes).

The Swiss company already has two other products in Phase III testing: ceftobiprole, a first-in-class, broad-spectrum antibiotic for resistant infections partnered with Johnson & Johnson, and alitretinion, a vitamin A derivative for refractory chronic hand dermatitis.

Basilea insists that BAL8557 has major sales potential, because of the rising incidence of invasive fungal infections in major pharmaceutical market. Currently available antifungal drugs are reported to fail in more than 50% of patients with acute invasive aspergillosis and in 20-30% of patients with candidaemia.